This is Villa Polissena, a Rococo house that used to belong to Princess Mafalda of Savoy, the second daughter of King Victor Emmanuel III of Italy and his wife, Elena of Montenegro.
In September 1925, she married the Landgrave Philip of Hesse. As a wedding gift, they received a house near Villa Ada, which the couple gave the name of Villa Polissena, in memory of Princess Polyxena Christina of Hesse-Rotenburg, second wife of Charles Emmanuel III of Savoy.
Today, villa is property of the Brachetti Peretti family of counts, who own Anonima petroli italiana, a large oil company in Italy.